The ventilator assisted breathing after endotracheal intubation is the main clinical measure adopted to treat respiratory failure, severe heart failure and surgical anesthesia. However, endotracheal intubation often induces ventilator-associated pneumonia, which may prolong the hospitalization time of a patient, increase the hospitalization cost, and may even lead to an increase in mortality. Ventilator-associated pneumonia often results from infection with multiple drug-resistant bacteria, and has become a medical problem. There are many causes for incidence of ventilator-associated pneumonia after endotracheal intubation, among others, the inhalation of secretions from the oral cavity, the pharynx and the nose is the most primary factor. Therefore, preventing secretions of the oral cavity, the pharynx and the nose from entering the lung can significantly reduce the incidence of ventilator-associated pneumonia.
At present, the main measures taken in clinical practice include: (1) periodic or sustained suction under the glottis; (2) on-demand or periodic suction of secretions from the oral cavity and the pharynx with a sputum suction tube; (3) periodic cleaning of the oral cavity and the pharynx; and (4) periodic monitoring of the balloon pressure, with the pressure maintained at a water column level of 20 to 30 cm. However, these measures have poor effects and cannot effectively prevent pharyngeal secretions from entering the lung, thereby causing the incidence of ventilator-associated pneumonia to be remained high. At present, suction with a sputum suction tube conventionally used in clinical practice is easy to cause mucosal injury and bleeding, and has a poor cleaning effect. In addition, the existing measures require quite cumbersome operations and large nursing workload.